This attractive little northern aster is quite unlike any other, and here at the western edge of its range is usually said to inhabit “acid bogs,” but that is far from a fair statement of its occurrence in Michigan. Here it grows mostly in the eastern Upper Peninsula, which is underlain with limestone, and it thrives in fens, especially patterned peatlands where there may be expanses of it over many hectares, sometimes with no sphagnum in sight. Gerdes (1998) documents a striking intermediate hybrid of this species with Doellingeria umbellata – though Nesom (2001) argues the possibility that this is O. ×blakei (Porter) G. L. Nesom (despite the nearest occurrences of the other parent, O. acuminata Greene being ca. 800 km distant) or even a new species. More recent molecular data (Brouillet, unpublished), however, support the hypothesis of a hybrid with Doellingeria umbellata.